In performing a surgical operation, especially an ophthalmic surgery such as a cataract operation, which involves cutting cornea or sclera through microscopic observation, an ophthalmic surgery knife or scalpel is used. Such a surgical knife is very small having, for example, a thickness of 0.10-0.30 mm and a width of 1.5-3.5 mm. Incisions made by the surgical knife will be closed either through a suture or through a natural adhesion without suture.
To achieve a natural adhesion of the incisions, such incisions must be made by an extremely sharp blade of the surgical knife. To have very sharp blades, cutting edges of the surgical knife must be sufficiently polished, thereby having mirror polished surfaces.
In an ophthalmic surgery, a surgeon uses a microscope to observe a magnified object to perform a very delicate surgery in an extremely small area to make an incision accurately.
Since such a microscope involves a lighting to sufficiently produce the magnified image of the object, the mirror polished edges of the surgical knife tends to cause a reflection of the lights or glare. Such a reflection or glare adversely affects the visibility of the object for the surgeon, making the surgical operation difficult.
Thus, a surgical knife having an anti-reflection treatment on a part thereof in a visual field through the microscope has been proposed. Such an anti-reflection treatment is made through a chemical process to form a large number of crater like bumps on the surface of the surgical knife or through a barrel buffing or sandblasting process to form irregularities on the surface of the knife. Because of the bumps or irregularities on the surgical knife, the light is reflected irregularly and randomly, thereby avoiding the glare or reflection in the surgical operation.
Although the surgical knife having the anti-reflection treatment is effective in eliminating the reflection by the surgical knife, the sharpness of the blade tends to be harmed because such irregularities of the surface extend to the cutting edges of the knife.
The sharpness of the surgical knife is very important in the ophthalmic surgery, since the above noted natural adhesion is largely dependent upon the smoothness of the inner surface of the incision. If the inner surface of the incision is rough, it may cause a distortion after suturing the incision or may cause astigmatism. Therefore, a successful surgical operation is dependent upon whether the surgical knife has sufficient sharpness. Especially, a high level of sharpness in the surgical knife is required in an ophthalmic surgical operation that involves cornea cutting since it requires a surgeon to make complicated incisions. However, the conventional method for producing a surgical knife is insufficient to achieve such a high level of sharpness while prohibiting reflection or emission of lights from the knife.